Cassette for accommodating a recording medium

Abstract

A write area (10) is formed as a writable area on a recording medium accommodating cassette by a printing process using a printing ink containing a proper amount of protein powder made of natural collagen as a main component. In the write area (10), owing to hydrophilic group of the protein powder, even when something is written therein with a water base pen, its ink can be prevented from being floated therefrom and hence the writing can be carried out satisfactorily.

What is claimed is: 
     
       1. A plastic cassette storage case having a cassette-accommodating portion in which a recording medium cassette is accommodated, comprising: a writable area printed at a predetermined position on an outer surface of said cassette storage case using a printing ink containing a predetermined amount of protein powder having a natural collagen as its main component;   wherein said writable area comprises a single writable layer printed on the outer surface of said case at the predetermined position, and wherein said natural collagen contains a hydrophilic group and has a particle size of about 5 μm, said natural collagen being dispersed in said single layer such that the spacing between the particles of the collagen and the hydrophilic group of said collagen allow water based ink to permeate into said single layer.   
     
     
       2. A plastic cassette storage case according to claim 1, wherein said printing ink is a printing ink which further contains a predetermined amount of inorganic pigment which has a particle size that is larger than the particle size of said protein powder. 
     
     
       3. A plastic cassette storage case according to claim 1, further comprising a case body and a case lid pivotally supported to said case body so as to pivot between an open position and a closed position, and wherein at least one of said case body and said case lid is made of a transparent plastic material.